Scottish Longitudinal Study

The Scottish Longitudinal Study (SLS) is a large-scale linkage study created using data from administrative and statistical sources. These include: census data from 1991 onwards; vital events data (births, deaths, marriages); NHS Central Register data (gives information on migration into or out of Scotland); and education data (including Schools Census and SQA data). More detail can be found in the Guides & Resources section of the SLS-DSU website.

The SLS includes a range of variables describing cultural, demographic, economic, health, education, ecological, housing and social data. Its research potential is considerable.

The SLS is a replica of the ONS Longitudinal Study (ONS LS), which has now been running for over 40 years. The ONS LS was designed as a 1% sample of the population of England and Wales. Initial data were extracted for a sample of the 1971 census, and then linked to administrative, vital events and health datasets through time. Although Scotland was originally included in the ONS LS, it was removed at an early stage because of the very small size of the Scottish sample.

The SLS and ONS LS are similar, but with a few key differences. Firstly the SLS is a 5.3% sample of the Scottish population as compared to the ONS LS 1% sample. Secondly the ONS LS contains data since the 1971 census, whereas the SLS begins from the 1991 census. Thirdly, there are a small number of variables which are not common to both LSs, most notably hospital admissions data and education data which are held in the SLS but not the ONS LS.

To create the SLS, approximately 274,000 individuals were selected using 20 random birthdates, and this data has now been linked to other datasets including vital events, health information, weather and pollution data, and census data from 1991 and 2011 (data from Census 2011 will be linked to the SLS in early 2014). For further technical information about the creation and development of the SLS dataset, including tracing statistics and other background information see the Technical Working Papers in the Outputs section of our site.

The SLS is supported and maintained by the SLS Development & Support Unit (SLS-DSU) with a safe-setting at the National Records of Scotland in Edinburgh.